The Krups 472-00 replacement Duo Filter helps to reduce chlorine and sediments from your water leaving you with clean and fresh water resulting in a better tasting coffee. Using the Krups 472-00 Duo Filters will also prolong the life of your coffee machine by reducing lime-scale build up. Each box of the Duo Filters comes with two filters and is recommended by Krups to be replaced every 2-3 months.